Assessment of the sustainability of the iodine-deficiency disorders control program in Lesotho.

BACKGROUND: Evaluation of the sustainability of iodine-deficiency disorders control programs guarantees successful and sustained virtual elimination of iodine deficiency. The Lesotho universal salt iodization legislation was enacted in 2000 as an iodine-deficiency disorders control program and has never been evaluated. OBJECTIVES: To assess the sustainability of the salt iodization program in Lesotho, 2 years after promulgation of the universal salt iodization legislation. METHODS: The proportion to population size method of sampling was used in 2002 to select 31 clusters in all ecological zones and districts of Lesotho. In each cluster, 30 women were selected to give urine and salt samples and 30 schoolchildren to give urine samples. The salt samples were analyzed by the iodometric titration method, and the ammonium persulfate method was used to analyze the urine samples. The chairperson of the iodine-deficiency disorders control program was interviewed on programmatic indicators of sustainability. SAS software was used for statistical analysis of the data. RESULTS: The urinary iodine concentrations of very few children (10.1% and 21.5%) and women (9.8% and 17.9%) were lower than 50 microg/L and 100 microg/L, respectively. At the household level, 86.9% of the households used adequately iodized salt. Only four indicators of sustainability have been attained by the salt iodization program in Lesotho. CONCLUSIONS; Iodine-deficiency disorders have been eliminated as a public health problem in Lesotho, but this elimination is not sustainable. Effective regular monitoring of salt iodine content at all levels, with special attention to iodization of coarse salt, is recommended, together with periodic evaluation of the iodization program.

Iodine status as determined by urinary iodine excretion in Lesotho two years after introducing legislation on universal salt iodization.

OBJECTIVE: Mild to severe iodine deficiency has been documented in Lesotho since 1960. To eliminate the persisting iodine deficiency, legislation on universal salt iodization was introduced in 2000 as a long-term public health intervention strategy. We assessed the urinary iodine status of school children and women of child-bearing age in Lesotho 2 y after the introduction of legislation on universal salt iodization. METHODS: A 31-cluster national survey was conducted in 2002 by using the proportion to population size method. In each cluster, 30 women ages 15 to 30 y and 30 primary school children ages 8 to 12 y were randomly selected to provide urine samples for urinary iodine analysis. Data were interpreted according to criteria of the World Health Organization, United Nations Children's Fund, and International Council for Control of Iodine Deficiency Disorders (2001). Statistical analysis was performed using SAS. RESULTS: We analyzed 912 urine samples from children and 924 from women. The median urinary iodine concentrations were 214.7 microg/L for children and 280.1 microg/L for women, indicating more than adequate iodine intake. Median iodine concentration was higher in the lowlands (256.0 microg/L in children and 329.9 microg/L in women) than in the mountains (99.30 microg/L in children and 182.6 microg/L in women). Analysis of the distribution of the data showed values below 50 microg/L in 10.1% of children and in 9.8% of women. In addition, 21.5% of children and 17.9% of women had urinary iodine excretion values below 100 microg/L. In contrast, 36% of children and 47.2% of women had urinary iodine concentrations in excess of 300 microg/L. CONCLUSION: Results of urinary iodine excretion measurements indicated that iodine deficiency has been eliminated as a public health problem in Lesotho. However, the high median urinary iodine concentration of women in the lowlands indicated the possibility of a risk of iodine-induced hyperthyroidism in vulnerable people.

Iodine content of salt 2 years after the introduction of the universal salt iodisation legislation in Lesotho.

The aim of the present study was to assess the impact of the universal salt iodisation legislation on I levels of salt at household, retail and entry level in Lesotho. We used a multistage proportion to population size method to select thirty-one clusters from all the districts and ecological zones of Lesotho. In each cluster, thirty households were randomly selected and salt samples were collected. Six salt samples from two randomly selected retailers in each cluster, and a total of 107 salt samples from all the commercial entry points in the country were also collected. Lesotho does not produce salt and it imports almost all its salt from South Africa. The salt samples were analysed using the iodometric titration method. The median I concentration of salt was 36.2 ppm at entry point, 37.3 ppm at retail level and 38.5 ppm at household level. At household level only 1.6 % used non-iodised salt and 86.9 % used adequately iodised salt. Of all salt collected at household level, 20.4 % was coarse salt, which was significantly less well iodised than fine salt. The study demonstrates a major achievement in the availability of iodised salt as well as household use of adequately iodised salt. Under-iodisation of coarse salt and non-uniformity of salt iodisation at the production site were observed. Therefore, there is a need for enforcement of the salt iodisation legislation especially at entry-point level to ensure that only iodised salt enters the country. During enforcement more emphasis should be given to iodisation of coarse salt.

Prevalence of goitre and urinary iodine status of primary-school children in Lesotho.

OBJECTIVE: To estimate the prevalence of goitre, urinary iodine status, coverage of supplementation of iodized oil capsules, and current use of iodized salt in children in Lesotho. METHODS: Cross-sectional study of children from 50 primary schools in Lesotho. Thyroid glands of children aged 8-12 years were measured by palpation and graded according to the WHO, UNICEF, and the International Council for the Control of Iodine Deficiency's (ICCIDD) joint criteria. The use of iodized oil capsules was determined by a structured questionnaire and verified with the children's health booklets. Iodine content of household salt samples was analysed. Casual urine samples were analysed for urinary iodine. FINDINGS: Median urinary iodine concentrations of 26.3 microg/l (range 22.3-47.9 microg/l) indicated moderate iodine deficiency. More children in the mountains than in the lowlands were severely iodine deficient (17.7% vs 1.9%). Adjusted prevalence of goitre (4.9%) increased with age, was higher in girls than boys, and ranged from 2.2% to 8.8% in the different districts; this indicated no public health problem. Overall, 94.4% of salt samples were iodized, and coverage of supplementation with iodized oil capsules was 55.1%. CONCLUSION: Mild-to-moderate iodine deficiency exists in Lesotho. Iodine deficiency was more severe in the mountains than the lowlands and is still a concern for public health. Use of iodized salt coupled with iodized oil supplementation effectively controls iodine deficiency disorders. Effective monitoring programmes would ensure the use of adequately iodized salt throughout Lesotho and serve to evaluate progress towards optimal iodine nutrition. Iodized oil capsule supplementation should continue in the mountains.